Page 1 of 3

gt200 ?

Posted: Wed Apr 19, 2017 8:03 pm
by steve chapman
Can anyone tell me what timinig people are using on there gt200 kits, I'm using a bgm box pipe ., steve

Re: gt200 ?

Posted: Wed Apr 19, 2017 8:25 pm
by Rich_T
With box pipes 18-19 degrees. With expansions 17-18 depending on rev range.

Re: gt200 ?

Posted: Wed Apr 19, 2017 8:43 pm
by steve chapman
Thanks for the reply Rich, thats what im curently running , the reason for the question is i had i slight seeze , and checked the plug and it was grey rather than a nice brown colour , my other settings are 30mm phbh 130 main , x13 on 2nd clip , 40 float, 55 pilot , any ideas? Steve

Re: gt200 ?

Posted: Thu Apr 20, 2017 7:08 am
by eden
which atomiser?
main is a little small... use 135

Re: gt200 ?

Posted: Thu Apr 20, 2017 9:59 am
by Rich_T
PM me the engine specification, and the history and we'll go from there. Like Eden says, the Main is normally 135.

Re: gt200 ?

Posted: Thu Apr 20, 2017 10:48 am
by drunkmunkey6969
Rich_T wrote:With box pipes 18-19 degrees. With expansions 17-18 depending on rev range.
Hey Rich, I'm quite surprised at the suggested 18/19 degrees on the box pipe.

Out of curiosity Rich, what's your personal reasoning on the differential between ignition timing on box pipes vs expansions? I'd be intrigued to know. Cheers, Dan.

Image

Re: gt200 ?

Posted: Thu Apr 20, 2017 12:47 pm
by Muppet
a lesser more spread return pulse is my guess on the box pipe

Re: gt200 ?

Posted: Thu Apr 20, 2017 6:00 pm
by steve chapman
hi Eden the atomiser is an av268, Steve

Re: gt200 ?

Posted: Thu Apr 20, 2017 6:12 pm
by steve chapman
Rich , the engine spec is as follows

60/110 gt crank , bgm box pipe , 30mm phbh with breathsweet ,x13 needle 2nd clip from top, av268, 55 pilot , 130 main
engine has done about 150 miles so far with no problems just started to take it to about 50mph over the last few days and as i say it nipped up on me , plug colour is light grey , any help would be great
regards , Steve

Re: gt200 ?

Posted: Thu Apr 20, 2017 9:50 pm
by Rich_T
The main is a bit weak but even so if you are still running it the plug should not be grey by any stretch. Does the engine tick-over nice and start first or second kick from hot and cold? Are you using a porcupine head and a copper head gasket, base packer and gaskets? How many of the packers and gaskets are GT parts. How old is the carb. When you had a nip up, what were you doing (apart from riding), accelerating, decelerating, what speed? How are you "running in" around town, long runs, are you giving it full throttle? What plug are you running?